It is found off Japan, Korea and Taiwan. It lives in schools, and is usually about 6 inches (15 cm) long, though it can grow up to 12 inches (30 cm) long.
It eats Sardines, Shrimp, Sprat and Squid.
Jack Mackerel is not as fishy tasting as Spanish Mackerel.
In Japanese restaurants, Jack Mackerel is often served cleaned but still live and twitching, served with grated ginger.
Jack Mackerel is also called “Horse Mackerel” in English, though that’s not a particularly good name to use as that is applied to other types of fish as well.
The word that the Japanese use, Aji, is actually loosely applied to several closely related fish, though properly they are distinguished in Japanese as “maaji,”, etc.